How does the Audi A7 engine improve fuel efficiency?

I am looking to buy an Audi A7 and I am wondering about its fuel efficiency. How does the engine contribute to the car's overall fuel economy?

The Audi A7 has a turbocharged engine that uses a small turbine to force more air into the cylinders, resulting in more efficient and powerful combustion.

The A7 also has a mild hybrid system which uses a small battery to assist the engine during acceleration, reducing fuel consumption and emissions.

The A7 also has a start-stop system that shuts off the engine when the car is idle, helping to save fuel and reduce emissions.